The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed ...The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed to enhance ignition performance.The LPWPI system can effectively prolong the discharge duration time,improve ignition efficacy,and increase the plasma penetration depth.Experimental comparisons with the traditional Spark Ignition(SI)system demonstrate that the LPWPI increased discharge duration to 2.03 ms,which is 45 times longer than that of the SI system,while also doubling the spark penetration depth to 24.1 mm.The LPWPI system achieved a discharge efficiency of 61.1%,significantly surpassing the SI system's efficiency of23.3%.These advancements facilitated an extension of the lean ignition boundary by approximately 22.7%to 39.3%.High-speed camera recordings reveal that the spark duration of the LPWPI system was extended to 2.1 ms,compared to 0.6 ms in the SI system.Ignition progress with LPWPI shows a sustained spark kernel without the flame residence stage observed in the SI system.The impressive performance of the LPWPI system suggests that it is a promising alternative for aero-engine ignition systems.展开更多
In recent years, tobacco lean production infrastructure is almost full-fledged through development, and professional service scope expands accordingly. Hence, the developing emphasis has transformed from hardware faci...In recent years, tobacco lean production infrastructure is almost full-fledged through development, and professional service scope expands accordingly. Hence, the developing emphasis has transformed from hardware facilities improvement to software updating of lean management and precise work. With related documents released by China Tobacco and Guizhou Tobacco, the achievement of comprehen- sive lean management probably becomes one of the key goals for the future devel- opment of tobacco business. The construction goal of tobacco leaves lean produc- tion management system is to internalize technology, information, human resources, material and other production elements into value stream of flue-cured tobacco pro- duction, and strict control value stream of input costs and output benefits, and then create management profit, promote enterprise, core competitiveness. The lean pro- duction management is both extension and expansion of modern tobacco agriculture, closely related to agricultural standardization and GAP management, which is based on professional service training and production machinery upgrading, with team management and station working as carriers, and information feedback, key quality monitoring and benefit evaluation as assessment references.展开更多
Surat city is continuously expanding with industrial development. Despite several flyovers, traffic congestion continues in the heart of city. Therefore, fresh transportation planning is at anvil. Simultaneously, furt...Surat city is continuously expanding with industrial development. Despite several flyovers, traffic congestion continues in the heart of city. Therefore, fresh transportation planning is at anvil. Simultaneously, further expansion plan is under consideration to create yet another, the 10th industrial zone. Purpose of this paper is to explore lean management based sustainable transport system for meeting the increasing needs of people and supply-chain. The research examines different mode of transportation like; vehicles on road, rail on the land, and steamers through the sea route to provide connectivity. This study may support the planners of the smart city. The study intends to find how lean management can be integrated to sustainable transport system meeting objectives of lean and sustainability both. Lean management system claims to be capable of eliminating all type of wastes including those associated with transport system. On the other hand, sustainable transport claims to meet the needs of people in personal economic lives, importantly respecting the need of future generations. Therefore, this applied research aims to find a lean and sustainable transport solution. This research work can be seen as descriptive type as it includes survey of location and fact finding enquiries.展开更多
BACKGROUND Epigenetic regulation of leptin(LEP)plays a critical role in metabolic disorders,yet its promoter methylation patterns in lean diabetic populations remain poorly characterized.Emerging evidence suggests DNA...BACKGROUND Epigenetic regulation of leptin(LEP)plays a critical role in metabolic disorders,yet its promoter methylation patterns in lean diabetic populations remain poorly characterized.Emerging evidence suggests DNA methylation may precede clinical hyperglycemia,offering potential for early risk stratification.While obesity-associated LEP methylation is well-studied,lean Asian populations who exhibit high diabetes prevalence despite lower adiposity,represent an underexplored cohort.This study hypothesizes that LEP promoter methylation in peripheral leukocytes decreases progressively from normoglycemia to prediabetes and type 2 diabetes mellitus(T2DM),correlating inversely with serum LEP levels in lean Chinese adults[body mass index(BMI)<24 kg/m^(2)].AIM To investigate LEP promoter methylation status and its association with serum LEP levels across glycemic states in lean Chinese adults.METHODS We enrolled 392 participants including 120 normoglycemic controls,94 prediabetes[44 impaired fasting glucose(IFG)/50 impaired glucose tolerance(IGT)],178 T2DM aged 40-60 years with BMI<24 kg/m^(2).Genomic DNA from peripheral leukocytes underwent bisulfite conversion followed by methylation-specific PCR to assess CpG methylation in the LEP promoter.Serum LEP was quantified via enzyme-linked immunosorbent assay,with other parameters measured through standard assays.Statistical analyses included analysis of variance,χ²tests,and Pearson correlation(Bonferroni-corrected P value).RESULTS Methylation frequencies declined progressively:59.2%(controls)reduced to 43.6%(prediabetes;IFG:38.6%,IGT:48%)reduced to 31.5%(T2DM)(all P<0.05 vs controls;T2DM vs IGT:P=0.030).Serum LEP levels increased significantly in T2DM(16.94±4.19μg/L)vs controls(11.33±3.10μg/L;P=0.002),with intermediate values in prediabetes(IFG:13.79±3.32μg/L;IGT:12.62±4.81μg/L).A near-perfect inverse correlation between methylation and LEP levels was observed(r=-0.95,95%CI:-0.97 to-0.92,P<0.001),persisting after adjusting for age and BMI(β=-0.91,P<0.001).CONCLUSION LEP promoter hypomethylation parallels worsening glycemic status in lean Chinese adults,suggesting its potential as a blood-based epigenetic biomarker for diabetes progression,pending validation in longitudinal cohorts.展开更多
Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the cr...Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.展开更多
ZSF1 lean rats are widely used as controls in cardiometabolic studies involving ZSF1 obese rats,which develop a cardiometabolic syndrome and diastolic dysfunction at a young age due to a double leptin receptor mutatio...ZSF1 lean rats are widely used as controls in cardiometabolic studies involving ZSF1 obese rats,which develop a cardiometabolic syndrome and diastolic dysfunction at a young age due to a double leptin receptor mutation(Lepr^(cp)and Lepr^(fa)).Although,lean littermates show no overt signs of cardiometabolic disease or diastolic impact,they belong to one of three genotypic variants,two of which carry one of the mutant Lepr alleles and,thus,doubt has been raised about their suitability as healthy controls.We compared 32-week-old female ZSF1 lean and Wistar rats regarding physiological,myocardial,vascular,skeletal muscle,and mitochondrial characteristics.Lean rats showed lower body weight but increased heart,kidney,and skeletal muscle mass.Despite thicker ventricular walls,systolic and diastolic function were preserved.Hemodynamically measured contractility was higher as underpinned by a higher mitochondrial respiratory capacity of LV fibers.However,left ventricular filling pressure was elevated,accompanied by increased ventricular stiffness.Endothelial function was preserved,but smooth muscle responsiveness was reduced,indicated by impaired SNP-induced relaxation.Passive vascular stiffness mediated by collagenous fibers was significantly higher in lean rats.Skeletal muscle function was mostly preserved,though maximal specific force of the EDL was reduced.Taken together,ZSF1 lean rats are physiologically different from Wistar rats as they display enlarged myocardial dimensions accompanied by increased blood pressure and an incipient diastolic and vascular stiffness.Therefore,our data indicate an early phase of passive compliance disorder in ZSF1 lean animals,which might become more pronounced at an advanced age.展开更多
Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for exa...Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.展开更多
This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The dat...This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.展开更多
TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method,and investigated for NO reduction with CO as the reducing agent under lean burn conditions.The microscopic structure and surface properties ...TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method,and investigated for NO reduction with CO as the reducing agent under lean burn conditions.The microscopic structure and surface properties of the catalysts were studied by N2 adsorption-desorption,X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,H2 temperature-programmed reduction and Fourier transform infrared spectroscopy.TiO2/γ-Al2O3 supported In/Ag is a good catalyst for the reduction of NO to N2.It displayed high dispersion,large amounts of surface active components and high NO adsorption capacity,which gave good catalytic performance and stability for the reduction of NO with CO under lean burn conditions.The silver species stabilized and improved the dispersion of the indium species.The introduction of TiO2 into the γ-Al2O3 support promoted NO adsorption and improved the dispersion of the indium species and silver species.展开更多
BACKGROUND The coexistence of sarcopenia and obesity is referred to as sarcopenic obesity(SO)and it has been hypothesized that the two components of SO may synergistically increase their negative effects. However, man...BACKGROUND The coexistence of sarcopenia and obesity is referred to as sarcopenic obesity(SO)and it has been hypothesized that the two components of SO may synergistically increase their negative effects. However, many uncertainties still surround this condition especially with regard to its potential negative effects on health outcomes.AIM To conduct a systematic review to determine the prevalence of sarcopenia among adults with overweight and obesity and to investigate whether SO was associated with a higher risk of type 2 diabetes(T2 D).METHODS This study was conducted in adherence with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Literature searches, study selection, methodology development and quality appraisal were performed independently by two authors and the data were collated by means of metaanalysis and narrative synthesis.RESULTS Of the 606 articles retrieved, 11 studies that comprised a total of 60118 adults with overweight and obesity of both genders met the inclusion criteria and were reviewed, revealing two main findings. First, the overall prevalence of sarcopenia is 43% in females and 42% in males who are with overweight and obesity.Secondly, the presence of SO increases the risk of T2D by 38% with respect to those without SO(OR = 1.38, 95%CI: 1.27-1.50).CONCLUSION A high prevalence of sarcopenia has been found among adults with overweight and obesity regardless of their gender and this condition seems to be associatedwith a higher risk of T2D. Clinician should be aware of this scenario in their clinical practice for the better management of both obesity and T2D.展开更多
BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic diseases in the world.Nowadays,the percentage of non-obese or lean patients with NAFLD is increasing.NAFLD in non-obese populations,e...BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic diseases in the world.Nowadays,the percentage of non-obese or lean patients with NAFLD is increasing.NAFLD in non-obese populations,especially the lean subgroup with a normal waist circumference(WC),might lead to more problems than obese individuals,as these individuals may not visit clinics for NAFLD diagnosis or ignore the diagnosis of NAFLD.If the precise characteristics of these populations,especially the lean subgroup,are identified,the clinicians would be able to provide more appropriate advice and treatment to these populations.AIM To investigate the prevalence,clinical characteristics,risk factors,and possible indicators for NAFLD in lean Chinese adults with a normal WC.METHODS People without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included.Their fatty liver index(FLI),abdominal ultrasonography results,and controlled attenuation parameter were all assessed.Genotyping for single-nucleotide polymorphisms associated with NAFLD was performed in another small group consisting of biopsy-proven NAFLD subjects and healthy controls.RESULTS A total of 2715 subjects who underwent routine health examinations were included in the study.Among 810 lean participants with a normal WC,142(17.5%)fulfilled the diagnostic criteria for NAFLD.Waist-height ratio,hemoglobin,platelets,and triglycerides were significant factors associated with the presence of NAFLD in these participants.The appropriate cut-off value of the FLI score in screening for NAFLD in the lean subjects with a normal WC was 25.15,which had a 77.8%sensitivity and 75.9%specificity.There was no significant difference in the single-nucleotide polymorphisms in the SIRT1,APOC3,PNPLA3,AGTR1,and PPARGC1A genes between lean subjects with and without NAFLD(P<0.05).CONCLUSION NAFLD is not uncommon in lean Chinese adults even with a normal WC.Metabolic factors,rather than genetic factors,may play important roles in the development of NAFLD in this population.A lower cut-off value of the FLI score in screening for NAFLD should be used for lean Chinese adults with a normal WC.展开更多
As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmos...As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmosphere without any treatment during coal mine,oil,and natural gas production,thus leading to energy loss and greenhouse effect.In general,it is challenging to utilize lean methane due to its low concentration and flow instability,while catalytic combustion is a vital pathway to realize an efficient utilization of lean methane owing to the reduced emissions of polluting gases(e.g.,NOxand CO)during the reaction.In particular,to efficiently convert lean methane,it necessitates both the designs of highly active and stable heterogeneous catalysts that accelerate lean methane combustion at low temperatures and smart reactors that enable autothermal operation by optimizing heat management.In this review,we discuss the in-depth development,challenges,and prospects of catalytic lean methane combustion technology in various configurations,with particular emphasis on heat management from the point of view of material design combined with reactor configuration.The target is to describe a framework that can correlate the guiding principles among catalyst design,device innovation and system optimization,inspiring the development of groundbreaking combustion technology for the efficient utilization of lean methane.展开更多
Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously em...Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy Li-S batteries.展开更多
基金co-supported by the National Natural Science Foundation of China(Nos.52376138 and 52025064)the Science Center for Gas Turbine Project,China(No.P2022B-Ⅱ-018-001)the Foundation Research Project,China(No.1002TJA22010)。
文摘The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed to enhance ignition performance.The LPWPI system can effectively prolong the discharge duration time,improve ignition efficacy,and increase the plasma penetration depth.Experimental comparisons with the traditional Spark Ignition(SI)system demonstrate that the LPWPI increased discharge duration to 2.03 ms,which is 45 times longer than that of the SI system,while also doubling the spark penetration depth to 24.1 mm.The LPWPI system achieved a discharge efficiency of 61.1%,significantly surpassing the SI system's efficiency of23.3%.These advancements facilitated an extension of the lean ignition boundary by approximately 22.7%to 39.3%.High-speed camera recordings reveal that the spark duration of the LPWPI system was extended to 2.1 ms,compared to 0.6 ms in the SI system.Ignition progress with LPWPI shows a sustained spark kernel without the flame residence stage observed in the SI system.The impressive performance of the LPWPI system suggests that it is a promising alternative for aero-engine ignition systems.
文摘In recent years, tobacco lean production infrastructure is almost full-fledged through development, and professional service scope expands accordingly. Hence, the developing emphasis has transformed from hardware facilities improvement to software updating of lean management and precise work. With related documents released by China Tobacco and Guizhou Tobacco, the achievement of comprehen- sive lean management probably becomes one of the key goals for the future devel- opment of tobacco business. The construction goal of tobacco leaves lean produc- tion management system is to internalize technology, information, human resources, material and other production elements into value stream of flue-cured tobacco pro- duction, and strict control value stream of input costs and output benefits, and then create management profit, promote enterprise, core competitiveness. The lean pro- duction management is both extension and expansion of modern tobacco agriculture, closely related to agricultural standardization and GAP management, which is based on professional service training and production machinery upgrading, with team management and station working as carriers, and information feedback, key quality monitoring and benefit evaluation as assessment references.
文摘Surat city is continuously expanding with industrial development. Despite several flyovers, traffic congestion continues in the heart of city. Therefore, fresh transportation planning is at anvil. Simultaneously, further expansion plan is under consideration to create yet another, the 10th industrial zone. Purpose of this paper is to explore lean management based sustainable transport system for meeting the increasing needs of people and supply-chain. The research examines different mode of transportation like; vehicles on road, rail on the land, and steamers through the sea route to provide connectivity. This study may support the planners of the smart city. The study intends to find how lean management can be integrated to sustainable transport system meeting objectives of lean and sustainability both. Lean management system claims to be capable of eliminating all type of wastes including those associated with transport system. On the other hand, sustainable transport claims to meet the needs of people in personal economic lives, importantly respecting the need of future generations. Therefore, this applied research aims to find a lean and sustainable transport solution. This research work can be seen as descriptive type as it includes survey of location and fact finding enquiries.
文摘BACKGROUND Epigenetic regulation of leptin(LEP)plays a critical role in metabolic disorders,yet its promoter methylation patterns in lean diabetic populations remain poorly characterized.Emerging evidence suggests DNA methylation may precede clinical hyperglycemia,offering potential for early risk stratification.While obesity-associated LEP methylation is well-studied,lean Asian populations who exhibit high diabetes prevalence despite lower adiposity,represent an underexplored cohort.This study hypothesizes that LEP promoter methylation in peripheral leukocytes decreases progressively from normoglycemia to prediabetes and type 2 diabetes mellitus(T2DM),correlating inversely with serum LEP levels in lean Chinese adults[body mass index(BMI)<24 kg/m^(2)].AIM To investigate LEP promoter methylation status and its association with serum LEP levels across glycemic states in lean Chinese adults.METHODS We enrolled 392 participants including 120 normoglycemic controls,94 prediabetes[44 impaired fasting glucose(IFG)/50 impaired glucose tolerance(IGT)],178 T2DM aged 40-60 years with BMI<24 kg/m^(2).Genomic DNA from peripheral leukocytes underwent bisulfite conversion followed by methylation-specific PCR to assess CpG methylation in the LEP promoter.Serum LEP was quantified via enzyme-linked immunosorbent assay,with other parameters measured through standard assays.Statistical analyses included analysis of variance,χ²tests,and Pearson correlation(Bonferroni-corrected P value).RESULTS Methylation frequencies declined progressively:59.2%(controls)reduced to 43.6%(prediabetes;IFG:38.6%,IGT:48%)reduced to 31.5%(T2DM)(all P<0.05 vs controls;T2DM vs IGT:P=0.030).Serum LEP levels increased significantly in T2DM(16.94±4.19μg/L)vs controls(11.33±3.10μg/L;P=0.002),with intermediate values in prediabetes(IFG:13.79±3.32μg/L;IGT:12.62±4.81μg/L).A near-perfect inverse correlation between methylation and LEP levels was observed(r=-0.95,95%CI:-0.97 to-0.92,P<0.001),persisting after adjusting for age and BMI(β=-0.91,P<0.001).CONCLUSION LEP promoter hypomethylation parallels worsening glycemic status in lean Chinese adults,suggesting its potential as a blood-based epigenetic biomarker for diabetes progression,pending validation in longitudinal cohorts.
基金supported by the Jilin Scientific and Technological Development Program(No.YDZJ202201ZYTS669)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043 and 51604034).
文摘Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.
文摘ZSF1 lean rats are widely used as controls in cardiometabolic studies involving ZSF1 obese rats,which develop a cardiometabolic syndrome and diastolic dysfunction at a young age due to a double leptin receptor mutation(Lepr^(cp)and Lepr^(fa)).Although,lean littermates show no overt signs of cardiometabolic disease or diastolic impact,they belong to one of three genotypic variants,two of which carry one of the mutant Lepr alleles and,thus,doubt has been raised about their suitability as healthy controls.We compared 32-week-old female ZSF1 lean and Wistar rats regarding physiological,myocardial,vascular,skeletal muscle,and mitochondrial characteristics.Lean rats showed lower body weight but increased heart,kidney,and skeletal muscle mass.Despite thicker ventricular walls,systolic and diastolic function were preserved.Hemodynamically measured contractility was higher as underpinned by a higher mitochondrial respiratory capacity of LV fibers.However,left ventricular filling pressure was elevated,accompanied by increased ventricular stiffness.Endothelial function was preserved,but smooth muscle responsiveness was reduced,indicated by impaired SNP-induced relaxation.Passive vascular stiffness mediated by collagenous fibers was significantly higher in lean rats.Skeletal muscle function was mostly preserved,though maximal specific force of the EDL was reduced.Taken together,ZSF1 lean rats are physiologically different from Wistar rats as they display enlarged myocardial dimensions accompanied by increased blood pressure and an incipient diastolic and vascular stiffness.Therefore,our data indicate an early phase of passive compliance disorder in ZSF1 lean animals,which might become more pronounced at an advanced age.
文摘Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.
基金the financial support of the National Natural Science Foundation of China(Nos.U2141221 and 52076136)the National Science and Technology Major Project,China(Nos.J2019-Ⅲ-0004-0047 and Y2022-Ⅲ-0001-0010)+1 种基金the Center for Basic Science of Aero Engines and Gas Turbines Project,China(No.P2022-B-Ⅱ019-001)the Natural Science Foundation of Shanghai,China(Nos.22ZR1467900 and 23ZR1481400)。
文摘This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.
基金supported by the National Science & Technology Pillar Program(2012BAF03B02)National Natural Science Foundation of China(21101085,U1162203)+3 种基金Natural Science Foundation of Liaoning Province(2015020196)Doctoral Fund of Shandong Province(BS2015HZ003)Fushun Science & Technology Program(FSKJHT 201423)Liaoning Excellent Talents Program in University(LJQ2012031)~~
文摘TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method,and investigated for NO reduction with CO as the reducing agent under lean burn conditions.The microscopic structure and surface properties of the catalysts were studied by N2 adsorption-desorption,X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,H2 temperature-programmed reduction and Fourier transform infrared spectroscopy.TiO2/γ-Al2O3 supported In/Ag is a good catalyst for the reduction of NO to N2.It displayed high dispersion,large amounts of surface active components and high NO adsorption capacity,which gave good catalytic performance and stability for the reduction of NO with CO under lean burn conditions.The silver species stabilized and improved the dispersion of the indium species.The introduction of TiO2 into the γ-Al2O3 support promoted NO adsorption and improved the dispersion of the indium species and silver species.
文摘BACKGROUND The coexistence of sarcopenia and obesity is referred to as sarcopenic obesity(SO)and it has been hypothesized that the two components of SO may synergistically increase their negative effects. However, many uncertainties still surround this condition especially with regard to its potential negative effects on health outcomes.AIM To conduct a systematic review to determine the prevalence of sarcopenia among adults with overweight and obesity and to investigate whether SO was associated with a higher risk of type 2 diabetes(T2 D).METHODS This study was conducted in adherence with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Literature searches, study selection, methodology development and quality appraisal were performed independently by two authors and the data were collated by means of metaanalysis and narrative synthesis.RESULTS Of the 606 articles retrieved, 11 studies that comprised a total of 60118 adults with overweight and obesity of both genders met the inclusion criteria and were reviewed, revealing two main findings. First, the overall prevalence of sarcopenia is 43% in females and 42% in males who are with overweight and obesity.Secondly, the presence of SO increases the risk of T2D by 38% with respect to those without SO(OR = 1.38, 95%CI: 1.27-1.50).CONCLUSION A high prevalence of sarcopenia has been found among adults with overweight and obesity regardless of their gender and this condition seems to be associatedwith a higher risk of T2D. Clinician should be aware of this scenario in their clinical practice for the better management of both obesity and T2D.
基金National Key R&D Program of China,No.2017YFC0908900National Natural Science Foundation of China,No.81873565 and No.81900507Hospital Funded Clinical Research,Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,No.17CSK04 and No.15LC06.
文摘BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic diseases in the world.Nowadays,the percentage of non-obese or lean patients with NAFLD is increasing.NAFLD in non-obese populations,especially the lean subgroup with a normal waist circumference(WC),might lead to more problems than obese individuals,as these individuals may not visit clinics for NAFLD diagnosis or ignore the diagnosis of NAFLD.If the precise characteristics of these populations,especially the lean subgroup,are identified,the clinicians would be able to provide more appropriate advice and treatment to these populations.AIM To investigate the prevalence,clinical characteristics,risk factors,and possible indicators for NAFLD in lean Chinese adults with a normal WC.METHODS People without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included.Their fatty liver index(FLI),abdominal ultrasonography results,and controlled attenuation parameter were all assessed.Genotyping for single-nucleotide polymorphisms associated with NAFLD was performed in another small group consisting of biopsy-proven NAFLD subjects and healthy controls.RESULTS A total of 2715 subjects who underwent routine health examinations were included in the study.Among 810 lean participants with a normal WC,142(17.5%)fulfilled the diagnostic criteria for NAFLD.Waist-height ratio,hemoglobin,platelets,and triglycerides were significant factors associated with the presence of NAFLD in these participants.The appropriate cut-off value of the FLI score in screening for NAFLD in the lean subjects with a normal WC was 25.15,which had a 77.8%sensitivity and 75.9%specificity.There was no significant difference in the single-nucleotide polymorphisms in the SIRT1,APOC3,PNPLA3,AGTR1,and PPARGC1A genes between lean subjects with and without NAFLD(P<0.05).CONCLUSION NAFLD is not uncommon in lean Chinese adults even with a normal WC.Metabolic factors,rather than genetic factors,may play important roles in the development of NAFLD in this population.A lower cut-off value of the FLI score in screening for NAFLD should be used for lean Chinese adults with a normal WC.
基金financially supported by the National Natural Science Foundation of China(21922606,21876139)the National Natural Science Foundation of Shaanxi Province(2020JQ-919)+2 种基金the Shaanxi Natural Science Fundamental Shaanxi Coal Chemical Joint Fund(2019JLM-14)the Initial Scientific Research Fund for Special Zone’s Talents(XJ18T06)K.C.Wong Education Foundation。
文摘As a primary type of clean energy,methane is also the second most important greenhouse gas after CO_(2)due to the high global warming potential.Large quantities of lean methane(0.1–1.0 vol%)are emitted into the atmosphere without any treatment during coal mine,oil,and natural gas production,thus leading to energy loss and greenhouse effect.In general,it is challenging to utilize lean methane due to its low concentration and flow instability,while catalytic combustion is a vital pathway to realize an efficient utilization of lean methane owing to the reduced emissions of polluting gases(e.g.,NOxand CO)during the reaction.In particular,to efficiently convert lean methane,it necessitates both the designs of highly active and stable heterogeneous catalysts that accelerate lean methane combustion at low temperatures and smart reactors that enable autothermal operation by optimizing heat management.In this review,we discuss the in-depth development,challenges,and prospects of catalytic lean methane combustion technology in various configurations,with particular emphasis on heat management from the point of view of material design combined with reactor configuration.The target is to describe a framework that can correlate the guiding principles among catalyst design,device innovation and system optimization,inspiring the development of groundbreaking combustion technology for the efficient utilization of lean methane.
基金supported by the National Natural Science Foundation of China(21805162 and 21671096)National Key Research and Development Program(2018YFB0104300)+3 种基金Key Program of the Natural Science Foundation of China(51732005)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)Shenzhen Key Laboratory of Solid State Batteries(No.ZDSYS201802081843465)Research Support for Postdoctoral Scholars coming to Shenzhen(K19407556)。
文摘Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy Li-S batteries.
